In a conventional vise such as the type shown in French Pat. No. 341,243, the spindle is equipped with the cross pin, and the spindle nut is supported against the movable jaw in the clamping direction. In order to clamp a workpiece in place, the spindle, advanced after releasing the spindle nut, must be pulled back, and the spindle nut must be tightened with the spindle held in the retracted position. In order to release the workpiece, the spindle nut must be loosened and the spindle must be pushed forward.
In another known vise, such as shown in German Pat. No. 2,652,946, the spindle nut is equipped with the cross pin; this vise does not pertain to the aforementioned kind, because two fixed jaws are provided, and the pair of elements accordingly is not spring-loaded in the pivoting direction toward a fixed jaw. Between the spindle head and the movable jaw, a spring is effective which lifts the spindle in the direction of its axis. In order to clamp a workpiece in place, the released spindle must be depressed against the spring force, pivoted into the inclined position to be used, released, and thereafter must be tightened. In order to free the workpiece, the spindle must be released and depressed.
The invention as disclosed herein solves the problem of providing a vise which, while retaining the advantageous properties of the vises of the aforementioned type, can be manufactured without appreciable additional expenditure, but can be operated more easily and more quickly. In the vise according to this invention, it is sufficient for clamping a workpiece in position to tighten the spindle (or the spindle nut) and for releasing the workpiece to release the spindle (or the spindle nut), without it being necessary to additionally shift the spindle and hold same in the displaced position.
In the conventional vises (French Pat. No. 341,243; German Pat. No. 2,652,946), the releasing of the spindle merely disengages the anchorage of the cross pin in the series of slots; however, thereafter, the movable jaw cannot as yet be readily shifted backwards by hand, if it has jammed in the base due to an excessive tension force (if it has become canted in the guide due to the occurring torque). The pair of elements in these conventional vises cannot exert a force which would push the movable jaw back during release of the spindle, because the slot flank facing the fixed jaw extends approximately in the direction of the spindle, and the spindle nut or spindle head is supported against the movable jaw only for tightening purposes, but this nut or head can be lifted off its supporting surface (in the vise according to German Pat. No. 2,652,946, the spindle head is lifted off its supporting surface by the spring during loosening of the spindle).